论文标题
磁场梯度诱导
Magnon Polarons induced by a magnetic field gradient
论文作者
论文摘要
在这项工作中，我们报告了通过空间变化的磁场产生镁极化子激发的理论可能性。当应用磁场梯度时，Zeeman相互作用中磁场相互作用的空间依赖性会导致磁杆偶联，并且这种耦合直接取决于梯度的强度。还可以预测，磁场梯度的方向可以控制哪个声子极化夫妇到材料中的磁子。在这里，我们开发了任意（抗）铁磁体的磁杆偶联的计算，后来用于数值研究其后果。将这些结果与YIG中现象学磁弹性耦合获得的结果进行了比较，在那里我们表明，在YIG中看到的木polaron带隙也可以使用$ \ sim 0.1 $ t/m的磁场梯度获得，这可以通过当前的实验技术来实现。我们的结果提出了一种在任意材料中控制磁弹性耦合的新方法，并打开了一条新的途径，以利用镁质和自旋设备中的镁音波相互作用。
In this work, we report the theoretical possibility of generating magnon polaron excitations through a space-varying magnetic field. The spatial dependence of the magnetic field in the Zeeman interaction gives rise to a magnon-phonon coupling when a magnetic field gradient is applied, and such a coupling depends directly on the strength of the gradient. It is also predicted that the direction of the magnetic field gradient allows control over which phonon polarization couples to the magnons in the material. Here we develop the calculations of the magnon-phonon coupling for an arbitrary (anti)ferromagnet, which are later used to numerically study its consequences. These results are compared to the ones obtained with the phenomenological magnetoelastic coupling in YIG, where we show that the magnon polaron bandgap seen in YIG can be also obtained with a magnetic field gradient of $\sim 0.1$T/m which can be achieved with the current experimental techniques. Our results propose a new way of controlling the magnetoelastic coupling in an arbitrary material and open a new route to exploit the magnon-phonon interaction in magnonic and spintronic devices.
